Sensors based on optical fiber for measuring the current circulating through a conductor are known. Said sensors work according to the Faraday Effect, i.e., the magnetic field generated by the current circulating through the conductor causes a rotation in the polarization of light circulating through the optical fiber arranged around the conductor. The operation of a measuring equipment based on optical fiber consists of emitting light through an optical fiber towards a sensing portion in which the characteristics of the light are modified depending on the current circulating through the conductor, and analyzing the rotation caused in the polarization of light to determine the magnitude of the current passing through the conductor.
Current measuring equipment based on optical fiber in which the components forming the equipment are arranged in the proximity of the conductor, the sensing of which is to be achieved are known. For example, patent documents US20120286767A1 and WO2000026682A1 disclose current measuring equipment of this type. When the conductor, the sensing of which is to be achieved is arranged in a remote location, arranging all the elements making up the measuring equipment in said location can be a drawback, since some of the components forming the measuring equipment must be powered, for example.
In addition, current measuring equipment based on optical fiber in which the sensing portion and the rest of the measuring equipment are arranged spaced apart from and joined to one another by an intermediate fiber of indefinite length are also known. For example, patent document US20110115469A1 describes current measuring equipment comprising a light source emitting light towards a sensing portion through a standard single-mode fiber. The sensing portion comprises a sensing fiber wound around the conductor and a mirror on which the light is reflected. For the return of the light the sensor comprises, at the outlet of the sensing portion, a polarization splitter splitting the light in two components the polarizations of which are perpendicular. Each component is depolarized and then emitted through two intermediate fibers, one for each component, towards a respective photodetector. Splitting the light in two polarized components and subsequently depolarizing same, seeks to compensate for the alterations that can be caused by the intermediate fiber.